# CVE-2024-50043: nfsd: fix possible badness in FREE_STATEID

> A race condition in the Linux kernel's NFS server allows attackers to trigger use-after-free or refcount underflow errors, potentially leading to code execution or system crashes.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Oct 2024
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2024-50043, DEBIAN-CVE-2024-50043, GHSA-5q55-gh5r-h286, UBUNTU-CVE-2024-50043

## What is CVE-2024-50043?

CVE-2024-50043 is a critical use after free vulnerability in Linux kernel, published on 21 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix possible badness in FREE_STATEID

When multiple FREE_STATEIDs are sent for the same delegation stateid,
it can lead to a possible either use-after-free or counter refcount
underflow errors.

In nfsd4_free_stateid() under the client lock we find a delegation
stateid, however the code drops the lock before calling nfs4_put_stid(),
that allows another FREE_STATE to find the stateid again. The first one
will proceed to then free the stateid which leads to either
use-after-free or decrementing already zeroed counter.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-50043?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-50043?

Apply the vendor's patch.

## Is CVE-2024-50043 being exploited?

There is no known exploitation of CVE-2024-50043 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-50043 and fix it if it is affected.

What it is: CVE-2024-50043 is a critical use after free vulnerability in Linux kernel, published on 21 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-50043 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-50043/ (Markdown: https://insights.sbomify.com/CVE-2024-50043/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-50043
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-50043
- OSV: https://osv.dev/vulnerability/CVE-2024-50043

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-50043/
Summaries are generated and may contain mistakes; the official description above is the record.